Self Diagnosis Function; Overview; Abnormality Judgment Criterion - Sony PFM-50C1 Service Manual

3-2. Self Diagnosis Function

3-2-1. Overview

The self-diagnosis function of this model detects abnor-
mality by checking the power voltages, detecting tempera-
ture, detecting operation of fans and by checking EE-
PROM register and the watch timer using the A/D convert-
er. When any abnormality is detected, the self-diagnosis
function displays the abnormality by flashing the Standby
indicator and displays the detected data on the service
menu.
If the abnormal condition exceeds the allowable limit, it
forcibly activates the shutdown operation.
The self-diagnosis function detects operations of the
following points.
1. Detecting stoppage of fans and detecting failure of the
fan drive circuit
2. Detecting temperature increase of the power supply
block and shutting it down
3. Detecting temperature increase at the center of the top
of the PDP panel and shutting power supply down
4. Detecting temperature increase at the I/O block side of
the top of the PDP panel and shutting power supply
down
5. Detecting temperature increase at the left side of the
PDP panel and shutting power supply down
6. Detecting the communication error with each device
7. Detecting the EEPROM error
8. Detecting decrease of the watch backup power voltage
and detecting abnormal oscillation
9. Detecting PDP initialization error
10. Detecting chroma decoder initialization error
11. Detecting abnormal voltage of the internal power
supply and shutting it down
12. Detecting abnormal power-off sequence
If any abnormality is detected, the Standby indicator
flashes at the interval of 0.4 seconds continuously.
At the same time, the corresponding item shows the NG
indication the service menu.
The NG indication is not reset and is accumulated unless
the AC cord is disconnected.
If the abnormal condition exceeds the allowable limit, it
forcibly activates the shutdown operation and picture will
not be displayed any more.
At this time, the Standby indicator flashes to indicate that
the PDP unit is in the error mode as shown in Section 3-1.
3-2

3-2-2. Abnormality Judgment Criterion

1. Detecting stoppage of fans and detecting
failure of the fan drive circuit
Service Mode
Service Status
Fan & Temp Status
Fan Drive
Fan
P/S Temp
P/S Temp
NO ACK DEV
(1) Fan Drive : If the fan drive circuit is defective, "NG"
is displayed.
(2) Fan : If any of the four built-in fans stops its
rotation, "NG" is displayed.
2. Detecting temperature increase of the power
supply block and shutting it down
Service Mode
Service Status
Fan & Temp Status
Fan Drive
Fan
P/S Temp
P/S Temp
NO ACK DEV
(1) P/S Temp : If temperature inside the power supply
block exceeds 71dC, "NG" is displayed. If
temperature exceeds 76dC, the shutting-
down is activated.
: OK (1)
: OK (2)
: OK
: 44[dC]
: 0004
: OK
: OK
: OK (1)
: 44[dC]
: 0004
PFM-50C1/50C1E